Hi @yashwanth522,
There does need to be at least one record in order for it to get overwritten. The containing record can all have NULL values or you can UNION a dummy table containing a record so that there's always, at minimum, one going out. However, you will need to make sure your Tableau Dashboard can account for this dummy record appropriately.
A more dynamic approach would be as illustrated below.
Using the "Count Records" tool, this will always generate a record that represents how many records are in the data, including a count of 0 if there aren't any. This is an arbitrary value, but the safest way to ensure one field one record is created and holds no dependencies or requirements to data going into it. I then "Append" the original data to the count.
IMPORTANT:
- Count must be connected to the "Append" tool through the "T" Input anchor
- In the "Append" tool, you'll need to modify the default setting which will "Error on appends of more than 16 records" to "Allow All Appends"
The "Select" tool is optional, but I used it to remove the count field is then used to exclude that count field. Looking at the bottom container, it started with 0 records, but the output generated one record with NULL values.
Benefit of this approach is that if your data DOES have records, it won't generate additional records, as illustrated in the top container, which started with 1 record and ended with 1.
Workflow is also attached for you to review.
Hope this helps!
Jimmy
Teknion Data Solutions
